<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
  <script src="lib/vue.js"></script>
</head>
<body>
<div id="root">
  <div v-text="str"></div>
  <div v-html="str"></div>
</div>
<script>
  new Vue({
    el : '#root',
    data : {
      str : `
        <h3>12345</h3>
      `
    }
  })
</script>
</body>
</html>